249 research outputs found
Effect of wheat bran supplementation with fresh and composted agricultural wastes on the growth of Kenyan native wood ear mushrooms [Auricularia auricula (L. ex Hook.) Underw.]
Nutrient supplements and agricultural wastes used for mushroom cultivation are important in improving
establishment and production of mushrooms. Agricultural wastes such as sawdust, grass, sugarcane
bagasse, wheat straw and maize cobs have successfully been used for the production of Kenyan wood
ear mushrooms [Auricularia auricula (L. ex Hook.) Underw.]. However, the effect of varying
concentrations of wheat bran supplements on their productivity has not been fully researched. In this
study, fresh and composted agricultural wastes were supplemented with wheat bran at concentrations
of 0, 5, 10 and 20%. The cultivation experiment was arranged in a completely randomized design (CRD)
and replicated three times. Data was collected on days to spawn run, days to primordial initiation,
primordial concentration quality and biological efficiency. The data collected was subjected to analysis
of variance using SAS version 9.1. Mean separation was done using least significant difference (LSD)
and effects were declared significant at 5% level.
Key words: Wood ear mushrooms, fresh and composted agricultural wastes, wheat bran, Kenya
Plant Species in the Folk medicine of Kit Mikayi Region, Western Kenya
An ethnobotanical survey of medicinal plants used in Kit Mikayi area of Western Kenya was carried out in 2007. The area is adjacent to Lake Victoria, the second largest fresh water lake in the world. Being a shrine, an ethnobotanical survey was conducted with the aim of documenting the local plants of economic value which have over time attracted both local and foreign visitors. Thirty-seven species were documented, and their use values and informant consensus factors were determined. The results were considered as important in defining conservation priorities as well as for further investigation of the identified plants for possible pharmacological applications
Genetic variability of tissue cultured Sorghum bicolor (L) Moench as revealed by morphological traits and simple sequence repeats (SSR) markers
To evaluate their performance for seedling traits at seedling stage (under hydroponics), plant water relations under water stress and ultimately grain yield, and to estimate the genetic variability of the regenerates, the parent plants of local sorghum cultivars in Kenya using simple sequence repeats (SSR) markers were analyzed. The research involved Seredo, El Gardam and Mtama 1 sorghum cultivars. The TC (Tissue culture) regenerates were produced through somatic embryogenesis in Linsmaier and Skoog (LS) media augmented with an osmoticum, NaCl (100 mM) in attempt to improve the parent plant for water stress tolerance. The genetic variability was investigated using five SSR markers and seven morphological traits associated with water stress tolerance. The amplified DNA fragments were screened by gel electrophoresis using 2% agarose. Cluster and principal component analysis (PCA) were done using NTSYS-pc version 2.2. The SSR detected 11 alleles with an average of 2.2 alleles per locus. The number of alleles per locus ranged from two to three and the allelic polymorphism information content (PIC) value ranged from 0.344 for Xcup14 to 0.730 for Xgap72 with an average of 0.559. These results show that the cultivars differed for morphological and SSR markers. The average genetic similarity based on the morphological traits (0.922 with a range of 0.845 to 0.989) was higher than SSR markers (0.625 with a range of 0.306 to 0.944). The results also show that the classification of these sorghum cultivars may be useful to the breeders to plan crosses for preferred traits. The results also show that the sorghum microsatellites can be used to distinguish the cultivars and to estimate genetic diversity due to somaclonal variation. Overall, this study shows that tissue culture technique might not add value in producing somaclonal variation in sorghum.Key words: Cultivars, tissue culture regenerates, water stress tolerance, simple sequence repeats
Determining efficient extraction procedure of phytochemicals from the fruit paste of Ziziphus abyssinica and Tamarindus indica.
Objective: To determine the most effective method of extracting metabolites from the two herbs Ziziphus abyssinica and Tamaridus. Indicus.Methodology and results: The methods used included cold and soxhlet extraction using methanol as the solvent and hot extraction using distilled water. To determine the efficiency in which compounds are extracted TLC was performed on silica gel aluminium plates using ethyl acetate: formic acid: glacial acetic acid: water (100:11:11:27). To determine the quantity of phenolic compounds in the extract, the Folin and Ciocalteau’s method (1927) was used, using Gallic acid in various concentrations. For the total quantity of flavonoid compounds, the method of Miliauskas et al. (2004) was used. To determine the Proanthocyanidin content in the extract a method previously reported by Ayoola et al, 2006 was used. To measure the antioxidant capacity of the extracts the hydrogen donating or free radical scavenging activity, was measured using the stable radical DPPH. The compounds extracted by all the methods were about seven but the difference was noted when the individual compounds were analysed. The cold extraction on the herb extract of Z. abyssinica had significantly high amount of total phenols 1.99g/100g of sample than both soxhlet and water extraction with 1.51g and 0.61g/100g of sample respectively. The results of T. indicus indicate that the extracts from the soxhlet and cold extraction methods contained a significantly low amount of all the three compounds compared to the water extractsConclusion and application of results: The method best suited for obtaining extracts from the two herbs T. indicus and Z. abyssinica is, cold method of extraction with methanol as the solvent for Z. abyssinica and hot extraction using distilled water for T. indicus. The results obtained give guidance to the fact that using both herbs would result in a better preservative than using one herb since the identified compounds would complement each other.Key words: Antimicrobial, antioxidant, phytochemicals and Radical scavenging activity
Critical analysis of tillage practices with fertility levels in maize and populations in beans as adaptation measures to climate change to enhance food security at Kabete
Trials were carried out in 2012/2013 short and 2013 long seasons at Kabete site representing a warm
and wet environment in Kenya to determine, the appropriateness of combining fertilizer levels for
maize and population levels with tied ridges for beans, as adaptation measures under changing
climate. The maize experiment consisted of three fertilizer levels of 0, 20 and 40 kg/ha N while the
bean experiment had three spacings of 12, 15 and 20 cm in a split plot design. The experiments were
replicated thrice and consisted of conventional tillage and tied ridges as main plots representing the
two soil water management practices while the three soil fertility levels (in maize N0, N20 and N40) or
spacing options (12, 15 and 20cm) were sub plots in a Completely Randomized Block Design. The
ridges were tied at intervals of 1 m and spaced at recommended crop spacings (i.e. 75cm for maize and
45cm for beans) and the crop planted on the slope of the ridge in 6 by 5 m plots. Basal phosphate (P205)
fertilizer in the form of Triple Superphosphate was applied at planting time at the rate of 40kg/ha.
Nitrogen in the form of Calcium Ammonium Nitrate was applied at 20 Kg/ha in the 20 and 40 N
treatments at planting and further 20kg/ha N top dressed in the 40 treatment level. Harvesting was
done at physiological maturity of grain which was air dried. Statistical analysis was done of the
treatments and comparisons done of the adaptation advantages of the treatments. Tied ridging
increased maize yields at the medium fertilizer level of 20 (+5.22%) but were negative under both zero
(-15.56%) and 40 kg/ha application of fertilizers (-5.42%). In the short season, increased bean spacing
from 12 to 20 decreased yields under normal (-13.6%) and tied ridges (-37.3%) but remained higher at
populations of 12 and 15. In the long season increasing bean population from spacing of 12 cm to 20 had
no advantage and under tied ridging compared to normal tillage. Tied ridging as a climate change
adaptive measure should not be instituted as a blanket recommendation across rainfall regimes, crops,
fertilization levels or plant populations and is more advantageous in drier seasons
An intensive, active surveillance reveals continuous invasion and high diversity of rhinovirus in households
We report on infection patterns in 5 households (78 participants) delineating the natural history of human rhinovirus (HRV). Nasopharyngeal collections were obtained every 3–4 days irrespective of symptoms, over a 6-month period, with molecular screening for HRV and typing by sequencing VP4/VP2 junction. Overall, 311/3468 (8.9%) collections were HRV positive: 256 were classified into 3 species: 104 (40.6%) HRV-A; 14 (5.5%) HRV-B, and 138 (53.9%) HRV-C. Twenty-six known HRV types (13 HRV-A, 3 HRV-B, and 10 HRV-C) were identified (A75, C1, and C35 being most frequent). We observed continuous invasion and temporal clustering of HRV types in households (range 5–13 over 6 months). Intrahousehold transmission was independent of clinical status but influenced by age. Most (89.0%) of HRV infection episodes were limited to <14 days. Individual repeat infections were frequent (range 1–7 over 6 months), decreasing with age, and almost invariably heterotypic, indicative of lasting type-specific immunity and low cross-type protection
Yellow Fever Outbreak, Southern Sudan, 2003
In May 2003, an outbreak of fatal hemorrhagic fever, caused by yellow fever virus, occurred in southern Sudan. Phylogenetic analysis showed that the virus belonged to the East African genotype, which supports the contention that yellow fever is endemic in East Africa with the potential to cause large outbreaks in humans
Yellow Fever Outbreak, Imatong, Southern Sudan
In May 2003, the World Health Organization received reports about a possible outbreak of a hemorrhagic disease of unknown cause in the Imatong Mountains of southern Sudan. Laboratory investigations were conducted on 28 serum samples collected from patients in the Imatong region. Serum samples from 13 patients were positive for immunoglobulin M antibody to flavivirus, and serum samples from 5 patients were positive by reverse transcription–polymerase chain reaction with both the genus Flavivirus–reactive primers and yellow fever virus–specific primers. Nucleotide sequencing of the amplicons obtained with the genus Flavivirus oligonucleotide primers confirmed yellow fever virus as the etiologic agent. Isolation attempts in newborn mice and Vero cells from the samples yielded virus isolates from five patients. Rapid and accurate laboratory diagnosis enabled an interagency emergency task force to initiate a targeted vaccination campaign to control the outbreak
Adapting Agriculture to Climate Change: An Evaluation of Yield Potential of Maize, Sorghum, Common Bean and Pigeon Pea Varieties in a Very Cool-Wet Region of Nyandarua County, Central Kenya
Three experiments were conducted to evaluate the performance of maize, sorghum, common bean and pigeon pea varieties under different water management in a cool and wet region of Central Kenya, as a part of the studies at analogue sites. The first experiment evaluated the growth and performance of three varieties (early maturing: EM, medium maturing: MM and late maturing: LM) of maize (Zea mays L), sorghum (Sorghum bicolor L.), pigeon pea (Cajanus cajan) and common bean (Phaseolus vulgaris L.). The second experiment evaluated maize and sorghum response to water conservation and three fertiliser rates (0, 20 and 40 kg N/ha). The third experiment assessed the effect of water conservation measures on crop yields of common bean and pigeon pea grown under three plant densities (low, medium and high). Tied ridge tillage was used as the water conservation measure and disc plough as the control in the second and third experiments. Maize, sorghum, pigeon pea and common bean took more than 180, 245, 217 and 95 days respectively, to reach physiological maturity. The MM maize variety (DK8031), EM pigeon pea variety (ICPL 84091) and LM common bean variety (GLP 24) yielded the greatest grain of 4,938, 881 and 620 kg/ha respectively, among the respective crop varieties. The sorghum varieties were attacked by fungal and rust diseases leading to yield losses in all seasons. Soil water conservation in general did not have a significant effect on crop yield though there were yield improvements. In the plant density trial, the medium plant densities of pigeon pea (33,333 pl/ha) and common bean (148,148 pl/ha) resulted in the greatest grain yields. The highest grain yield of maize (4,184 kg/ha) and sorghum (47 kg/ha) was obtained in plots with 20 kg/ha of nitrogen fertilizer. Based on the results of this study, pigeon pea and common bean can be introduced in the farming systems to improve crop diversity. The production of the tested sorghum varieties should be discouraged in this region because they are prone to fungal and rust diseases due to the cold and wet weather conditions
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